The study, published in The Lancet, found rates before and after legalisation in 2002 were comparable.

The figures have been leapt upon by advocates of a change in the law here, who say they show there would be no “slippery slope” towards more people choosing assisted dying.

But opponents warn it shows there has been a big rise in the use of methods that border on assisted dying, such as continuous deep sedation.

In 2002 The Netherlands became the first country in the world to legalise assisted dying, although it had been tolerated since the 1970s. The rules only cover patients with an incurable condition who face unbearable suffering.

The Dutch academics found that between 1990 and 2001 the rate of euthanasia and assisted suicide cases rose from 1.9 to 2.8 per cent of all deaths.

By 2005 - in the immediate aftermath of legalisation - the rate had dropped to 1.8 per cent, but by 2010 it had risen again to 2.9 per cent.

They concluded rates before and after legalisation were “comparable”.

Prof Ray Tallis, a retired geriatrician, and chairman of the group Healthcare Professionals for Assisted Dying, said the figures were “very reassuring”.

He said: “The ‘slippery slope’ worry, the idea that the numbers choosing to end their lives early will just get out of control, is not supported by this study.”

What is more, he said that reporting of assisted dying cases had improved thanks to legalisation.

“Legal sunlight is the best way of securing patient safety,” he argued, describing the current situation in Britain as “clinical, ethical and legal sludge”.

But Dr Peter Saunders, campaign director of the group Care Not Killing, said: “A careful examination of the figures tells a very different story.”

The numbers dying after continuous deep sedation (CDS) had risen from 5.6 per cent in 2001 to 12.3 per cent in 2010, he said.

CDS involves patients being given large doses of drugs that do not kill, but leave patients essentially unconscious in their final days. Used in particular for cancer patients, it has been described as “slow euthanasia”.

The proportion dying after “intense alleviation of symptoms” had also risen, from 20.1 to 36.4 per cent.

“It is not at all clear how many of these two categories of cases involved the explicit intention to end life,” said Dr Saunders.

“But it appears that Dutch doctors have kept the euthanasia figures low simply by choosing to end patients’ lives in ways other than administering paralysing drugs or barbiturates.”

He concluded: “The UK should take warning. The Dutch figures reveal incremental extension after legalisation which is being carefully and skilfully disguised.”

However, one study, by Bart’s and the London School of Medicine and Dentistry, found CDS is used more frequently in Britain - in 16.5 per cent of cases.

Professor Clive Seale, the author, suggested that could be because euthanasia was not a legal option here.

The British Medical Association recently voted to maintain its position of opposition to a change in the law.

A spokesman said: "Therefore the BMA’s current policy remains firmly opposed to the legalisation of assisted dying and we will not be lobbying for any change in the law.”